AEC3: Adding another config parameter and matching json reader with config

This CL:
-Adds another config parameter that controls the duration of the initial
state.
-Adds reading of that parameter in audioproc_f from the json settings file.
-Adds missing reading of another parameter in audioproc_f from the json
settings file.

Bug: webrtc:8671
Change-Id: Ie6164c360492de5e6b0ade8838bbabe214560b5e
Reviewed-on: https://webrtc-review.googlesource.com/94621
Reviewed-by: Jesus de Vicente Pena <devicentepena@webrtc.org>
Commit-Queue: Per Åhgren <peah@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24360}

modules/audio_processing/test/audio_processing_simulator.cc

@@ -210,6 +210,10 @@ EchoCanceller3Config ParseAec3Parameters(const std::string& filename) {
     ReadParam(section, "shadow", &cfg.filter.shadow);
     ReadParam(section, "main_initial", &cfg.filter.main_initial);
     ReadParam(section, "shadow_initial", &cfg.filter.shadow_initial);
+    ReadParam(section, "config_change_duration_blocks",
+              &cfg.filter.config_change_duration_blocks);
+    ReadParam(section, "initial_state_seconds",
+              &cfg.filter.initial_state_seconds);
   }
 
   if (rtc::GetValueFromJsonObject(root, "erle", &section)) {